JPH05503200A - printing device - Google Patents

Abstract

Printing apparatus particularly suited to provide a hardcopy of an image produced by medical imaging equipment or the like. The apparatus produces an area modulation hardcopy having a large number of gray levels per area modulation cell (pixel) by generating in substantially adfacent columns units of subpixels called pels. The pels have an initial size that is increased by the addition of subpels referred to as slices.

Description

[Detailed description of the invention] printing device Inquiries about related applications This application is a U.S. patent application filed on the same day and filed together with Sequential numbers (our case numbers 7581.7650.7652.7653, and 76 54).

Background of the invention 1. Field of invention The present invention generally relates to a method and method for obtaining copies of images obtained in electronic form. With respect to equipment, in particular, by way of example and without limitation, X-ray equipment, CAT scanners, etc. Images generated by medical imaging equipment such as imaging equipment, MR equipment, and ultrasound equipment The present invention relates to a method and apparatus for obtaining a hard copy of.

2. Description of conventional technology The hard copy is, for example, D, G, Herzog. ) f: according to rM111 formation f: paper entitled image tube copy output J ( J. Imaging Technology, Volume 13, No. 5, 1987 , pp. 167-178). images that can be transferred and processed without image deterioration. Usually hard A copy is an image printed onto a transparent sheet that allows light to pass through the medium. reflect light into an image on something that can be viewed visually or on an opaque material. This allows the image to be viewed visually. ” is defined as Ru. By those skilled in the art, electronically generated redactions are Many attempts have been made to produce devices for making code copies.

A device for obtaining a hard copy typically includes a group of sensors, a computer, etc. image data processing system, or storage device hardcopy service. It is well known to receive image information as output from a data source. this can receive image data in either analog or digital form. However, the general trend in this technology is to receive image data in digital form. It is to take. Furthermore, such devices typically include (al) for reservation processing and and/or for formatting input image data; and fb) e.g. print media. to compensate for nonlinearities in the image or to enhance image shading by modifying the device transfer function. with buffers, memory, lookup tables, etc. to compensate for or provide There is. Furthermore, such hardware devices typically include energy shaping mechanisms. an image generating subsystem such as a laser beam or a CRT beam; Supporting electronics for converting the energy source into a focused point for scanning across the media It is also equipped with

There are certain important image quality parameters that must be considered when designing hardcopy equipment. There is data. The first important image quality parameter is resolution. Most mapping devices are , has the ability to record thousands of image elements (pixels) on a medium. Separate individual pixels The ability to differentiate, or smooth the image from pixel to pixel, is determined by the resolution specification. be. The second important image quality parameters are raster and banding. raster and banding are artifacts that normally appear in pixels due to pixel recording systems. It is.

A raster is the result of an imperfect match of scan lines, resulting in a density in pixel space. Appears as a regular pattern of modulation. Banding, on the other hand, refers to the arrangement of pixels on a medium. caused by non-uniformity across or along the scan line. It appears as a regular or irregular pattern of density changes. Bandin The appearance of the tag depends on the source of the placement error, and the human visual system is highly sensitive to placement errors. Therefore, even a placement error of about 1% can be recognized. as a result , the requirement for banding is necessary to obtain accurate pixel and scan line placement. The costs involved must be carefully considered.

The third important image quality parameter is geometric fidelity. Geometric fidelity specifications defines the precision with which pixels are placed on the medium and how the medium is ultimately used. It is related to crab.

The fourth important image quality parameter is density fidelity.

The specification for density fidelity is the output of an input digital value (or analog voltage). It defines the transfer function to density. This specification provides the ability to transfer values to density, and the transfer functionality of any replication process utilized. The transfer function is specific It depends on process variables as well as the nature of the medium used. density fidelity The gender specification can be separated into four parts. That is, (a) absolute concentration (b) Relative density vs. input signal transfer function; (C) Area modulation vs. continuous tone recording , and (d) 8 degree uniformity.

The first of the three parts, the absolute density repeatability, is the same for a given input signal. Refers to the ability of a hardcopy device to consistently produce density values. three parts The second one, the relative density versus input signal transfer function, i.e., the tone scale, is useful for certain applications. In some applications, we exploit the linear density versus input signal transfer function, while in other applications we use the intentional Use distortion to adjust, compensate, or enhance shading in certain parts of the density range. It is related to the fact that something is done. The shape of the relative concentration versus input signal transfer function is digital can be adjusted using a correction lookup table placed in the input signal processing path. In addition, these tables can be fixed, positionally adjusted via panel control, or or can be loaded remotely via the control interface. .

Furthermore, if the relative density versus the shape of the input signal transfer function is important, media processor control related to control, periodic inversion function measurements, and periodic correction lookup table updates; A behavioral scenario is required. The third of these parts, area modulation vs. continuous tone Records will be explained in more detail below. Finally, the fourth of these parts The uniformity of the density produces a uniform and flat range over the entire mapped region. , refers to the capabilities of a hardcopy device.

Continuous tone recording records gray levels, such as those observed in photographs and natural scenes. Has a clear continuous pair of levels. This typically applies to e.g. printed dots. This is in contrast to area modulation recording, which consists of geometric patterns. Here, large This technology uses a pattern of dots of varying intensity to record halftones. Note that it is often referred to as a record. Halftone recording uses a regular array of The size of the printed dots can be changed to match the gray scale by the human eye. It is designed to give a range of gradations that can be sensed.

As is well known to those skilled in the art, variations in the size of printed dots can be For example, it causes a change in the percentage of light reflected from the printed image, and the result Continuous gray scale creates the illusion of gray scale as a halftone It can also be made almost equivalent to a record. The half I-n record is basically two. value, but - when viewed, the halftone recorded image is similar to that of Runecoby. Sometimes we hope that.

However, halftone recordings contain spatial frequencies that are not included or rare in the original image. This spatial frequency is complicated by the presence of a number of produce undesirable moiré patterns or other artifacts in It may result in cheating.

As disclosed in the prior art, binary devices, i.e. do not have gray scale capability Grayscale representation by devices that display or print dots of a fixed size. In one of the halftone recording methods to achieve Each halftone cell is an individual print or display unit, here named a bell. Consists of one or more clusters. The most common shape of a halftone pixel is , is an N×N square bell matrix with bells of fixed binary size.

The general idea of this method is to print a calculated number of bells within a halftone pixel or displays an average gray scale approximately equal to the average density value of the corresponding part of the original image. The aim is to obtain a skill level. For example, traditional halftone recording methods like this In one, the bell within one pixel is divided to form a single 71-ftone pixel. imitates, and furthermore, another of these prior art halftone recording methods. , the bells are distributed in a predetermined manner. In addition, there is also a process called “error diffusion”. Another such prior art halftone recording method involves The decision to print or not print is made using locally scanned density information from the original image as well as Based on the grayscale density error caused by already processed neighbors in the recording. I'm doing it. In addition to the above, those skilled in the art will understand that halftone recording is based on grayscale The level is reproduced in an average sense for one pixel, but the pixel size is too large. If the image is too large, the resolution of subtle details in the image may be lost.

All of the halftone recording methods described above print or display a fixed binary size. It discloses the use of dots. In contrast, U.S. Pat. No. 87 states that each pixel to be printed or displayed has a fixed number of gray scale levels. Discloses a halftone recording method that is programmably adjustable to have one ing. This patent discloses a halftone recording device that (a) records the original image; Image input data for scanning and corresponding to the gray scale level of the pixels of the original image. Image data input, such as a CCD scanner, to generate an array of data (b) receiving the array of image input data and calculating an array of print values; A process in which each printed value corresponds to one of a fixed number of gray scale levels. apparatus, and (C1 the size of the dot corresponding to one of said fixed gray scale levels) The present invention includes a printing device capable of printing pixels having a sharpness.

In addition, the above patent discloses that each pixel corresponds to one of a fixed number of gray scale levels. A printing machine capable of printing pixels having the size of The invention discloses that the invention includes a device for varying the energy required to produce the dots that are Ru. Further, the above patent states that the energy required to generate the printed dots is typically a defined shape of an electrical signal pulse having a given time length and a given voltage level It is also disclosed that there are. Finally, in the above invention, the changes in energy are as follows: Parameters of the electrical signal pulse, i.e. on-time part (duty cycle), Disclose that it can be affected by changing the pressure level or current flow. ing.

U.S. Pat. No. 4,661,859 produces pixels with variable gray scale. The present invention discloses an apparatus that accomplishes the following. In particular, this is a -dimensional electronic halftone generation A digital data source that discloses the system and represents the pixel gray scale; a counter that stores data, and digital data that represents each pixel in response to the counter. and pulse generation logic for activating the laser modulator according to the data.

More specifically, a 6-bit data word is used to generate 64 gray pixels for a 1- pixel. represents one of the color scale levels, and the pulsing logic activates the laser at a given time. A predetermined value that determines a predetermined gray scale level for that pixel by It responds to the data word by generating a long or wide pulse.

Despite the above-mentioned prior art halftone recording method and device, the technology does not There remains a need for methods and apparatus that can quickly reproduce realistic images. The method and apparatus provide strong gray scale without sacrificing resolution. The method and apparatus are particularly suitable for X-ray equipment, CAT scans, etc. equipment, MR equipment, ultrasound equipment, etc. It is particularly suitable for reproducing captured images.

Summary of the invention Embodiments of the present invention describe methods for obtaining copies of images, particularly by way of example and without limitation. Examples include medical photocopying equipment such as X-ray equipment, CAT scan equipment, MR equipment, and ultrasound equipment. Method and apparatus for obtaining a hard copy of an image being produced by an imaging device The above identified needs are met by providing a method and apparatus. Ru. In particular, embodiments of the present invention produce area-modulated hard copies of images. The hard copy has a large number of gray levels per area modulation cell (pixel) and a powerful density sensitivity, for example one with multiple gray level steps. this is, achieved by pulse width modulating two differently sized printing radiation beams. will be accomplished.

Specifically, according to a preferred embodiment of the invention, the printing press prints an image in a reflective or transparent manner. The intensity level of the emitted radiation is obtained as digital input image data, i.e., for measurement. means for interpolating and/or processing said digital input image data to A digital pixel corresponding to an area on the medium, called an area modulation pixel, consisting of subunits that are means for obtaining digital intensity levels; each of said digital intensity levels in a predetermined pattern of bells; and means for providing a drive signal to a laser radiation source to activate said source. means for printing a predetermined pattern of said bells on a medium, said source comprising two printing radiation beam sources of different sizes; It is formed by pulse width modulating a beam source of different sizes.

In a further embodiment of the invention, a printing press is provided for enhancing the accuracy of high density copies. The term "printing white" is used for writing purposes. A dark medium has the highest density, i.e. total black, and as the density decreases, the amount of radiation increases. Use of a medium in which the beam, e.g. laser radiation, reduces the black area It shows the law.

Drawing description The novel main points that are considered to be the characteristics of the present invention will be described here, including their organization and operation. Both methods of production are identified and described, along with other purposes and advantages. The following illustrative embodiments are best understood when read in conjunction with the accompanying drawings.

FIG. 1 shows a laser beam used to write area modulated pixels in an embodiment of the invention. The ``brush'' of the brush is shown in the shape of a picture.

Figures 2A-2T show various 90μm x 90μ The configuration pattern of the bell for the gray scale level of m pixels is shown in the form of a picture. vinegar.

FIG. 3 shows a block diagram of an embodiment of the invention.

FIG. 4 is a block diagram of a pixel generator manufactured in accordance with the present invention.

Figure 5 shows the difference between the configurations of 60 μm x 60 μm pixels and 90 μm x 90 μm pixels. The comparison is shown in the form of a picture.

Figure 6 shows how the laser drive data is arranged for a 90μm x 90μm pixel. Show what you did.

detailed description A printing device manufactured according to the invention produces a hard copy of an image. and the image may be in a number of different formats familiar to those skilled in the art. It can be anything. For example, the image may be captured by X-ray equipment, CT scanning equipment, MR equipment , can also be medical images produced by equipment such as ultrasound equipment, etc. However, it is not limited to this. In addition, the image may be digital or is in analog form, such as videotape, optical disk, magnetic disk, etc. It may be recorded on a storage medium.

Hard copies produced by embodiments of the invention may be produced by e.g. produced in a high-resolution thermal medium that forms images in response to intense radiation such as .

A suitable medium for preparing hardcopy images using embodiments of the invention is Mu, Earl, Etzel (M.

R, Etzel) international patent application PCT/US 87103249 (International Publication No. W88104237, published on June 16, 1988) and the claimed thermal imaging material. Generating an image with the desired durability A detailed description of the preferred media material in terms of this is provided by Gu. See, Chan (K, C. Chang), entitled “Thermal Mapping Medium”, patent management number 7620, this special found in the patent application filed on the same date as the patent application and assigned to the assignee.

A preferred binary thermal imaging medium consists of a pair of sheets, at least one of which is It is a transparent, layered medium. This sheet is sandwiched between their inner surfaces, Initially, they have the imaging material preferentially sticking to one of them. heat radiation pal When exposed to a When the sheets are separated, the unexposed portions of the imaging material are exposed to the initial preferential adhesion. It sticks to one side of the sheet, while the exposed part has an inverted preferential adhesive. sheets, thereby allowing complementary images to be formed on each sheet. Wear. Suitable imaging laminate materials respond to intense imaging radiation for use in the present invention. A type of color/binder that can act to produce an image in a sequential manner. It consists of the following in order:

(1) a first lamellar web material, said web material being directed to said imaging radiation; Transparent and activated by heat upon exposure of the thermal imaging medium to short, intense radiation. and at least a surface band or layer of a polymerizable material.

(2) Adhesion to the surface band or layer of the heat-activatable polymeric material is greater than or equal to tack. an optical thermoplastic interlayer.

(3) a porous or particulate imaging material layer on the thermoplastic interlayer; or particulate imaging material prior to the surface zone or layer of the heat-activatable polymeric material. has an adhesiveness to the thermoplastic intermediate layer that is greater than or equal to the adhesiveness of the thermoplastic intermediate layer. . as well as, (4) coating the porous or particulate image forming material layer and covering the image forming material layer; A second laminar web material that is directly or indirectly laminated.

Thermal imaging media comprises a surface band or layer of heat-activatable polymeric material and a thermoplastic intermediate layer. radiation at the wavelength of the exposed source can be absorbed at or near the interface of , further converts the absorbed energy into thermal energy of sufficient intensity to rapidly transform the surface zone or layer. Can be quickly thermally activated. The thermally activated surface zone or layer cools rapidly to firmly adhere the thermoplastic intermediate layer to the first lamellar web material.

In this way, the thermal imaging medium can be imaged into a portion of it with sufficient intensity of radiation. Upon exposure, the thermoplastic interlayer and the imaging material become rigid and compatible with imaging. the first and second sheet-like web material after exposure with respect to the image; Upon separation of the lamellar web material, a second lamina of the imaging material and thermoplastic interlayer is removed. The first and second images are transferred to the first and second thin plates, respectively, by transfer to the plate-like web material. Formed on a shaped web material.

An optional thermoplastic interlayer provides surface protection and a second image on the second laminar web material. It gives the image its durability.

In this way, there are two ways to create a hard copy using a thermal hard copy medium. steps are required. One step is to expose the medium to an appropriate amount of heat. The process consists of producing a latent image and the other steps are processing the latent copies, whereby the second sheet is imaged The unexposed portions of the material and, in the preferred embodiment, are described in more detail below. So, keep a hard copy.

The preferred medium is of laminated construction, but two non-laminated sheets with equivalent functionality It will be obvious that the following may also be used to practice the invention.

The medium is named threshold or binary type film, so The laser is particularly suitable for exposing the media. That is, the medium When exposed above the threshold value, it has high shading and produces the greatest density change. On the other hand, below this threshold, no density is obtained at all.

The hard copy produced by an embodiment of the invention may consist of a large number of pixels. be. In particular, in a preferred embodiment of the invention, each pixel is approximately 60 μm x 60 μm, approximately 90 μm It is μm×90 μm, or a variation of these sizes. Furthermore, hardco This technique is also called spatial dithering. generated by digital domain modulation. In area modulation, each pixel has a predetermined number of bases. a specific tone, density, or gray scale level for a single pixel. This method generates a predetermined number of bells. The technology is well known. As shown, the gradations of the area modulation have different densities when viewed from a suitable distance. Therefore, domain modulation is a medium that can produce only black and white bells. in the body, giving the illusion of a continuous tone image.

The following describes pixel size, bell size, and bell size for a preferred embodiment of the present invention. Describes the criteria used to determine configuration patterns.

In general, the copy resolution and what is required to produce a high quality copy of the image. It is well known in the art that there is a trade-off between the number of gray scale levels. This is true. For example, if an area modulation pixel consisting of nxm bells is used, two It is possible to reproduce n m + 1 different gray scale levels on the value medium. Furthermore , using the same Bell size, by increasing the area modulation pixel size, Thus, the number of gray scale levels can be increased. However, the pixel When increasing the size of , there is a loss of resolution in the hardcopy. On the other hand, too If fewer gray scale levels are available for printing, i.e. It can only be produced in too small a number of degrees. This was not in the original image , often when playing with large smoothly changing gray scale transitions. The appearance of the contour in the hard copy that occurs.

Therefore, in general, hardcopy products produced on printing presses using binary media are At least two measurements are important to assess quality. It is (11 areas change) tonal frequency, i.e., the number of area modulated pixels per linear inch; and (2) differentiation. Number of possible gray scale levels. Any required differences in hard copy The number of grayscale levels that will differentiate closely spaced grayscale levels Depends on the ability of the naked eye. For example, at normal reading distance, the human eye It is possible to detect a modulation of reflectance of approximately 0.5% at a spatial frequency of 1.0 m/m. , has been discovered. The opposite of this "just perceivable" modulation is that the human eye cannot perceive it. It is interpreted as the maximum number of gray scale levels that can occur. In other words, in the printing industry A rough rule of thumb is that a "just acceptable" picture should have a gray scale level of about 65. For high-quality copies, a level of 100 or higher is desirable; For medical applications, a level of 200 or higher is more appropriate.

In view of the above, in arriving at the selection of pixel and bell sizes for embodiments of the present invention, The following criteria were used. (1) A single pixel is invisible to the naked human eye and of high quality. It must be as small as required to produce a quality copy. (2) with an appropriate number of distinguishable gray scale levels and density from image to copy For a given bell size, in order to obtain a proper mapping of the level , the pixels must be large enough to contain a sufficiently large number of bells (as explained below). The ratio of the pixel size to the bell size is the bell included in one pixel. This, in turn, also determines the number of achievable gray scale levels. However, this ratio alone does not allow for one-to-one density mapping from image to copy. ), and (3) Bell patterns are surface depictions in copies. or contribute to contour formation.

In addition to the above, we have shown that the human eye changes grayscale levels as a linear function of intensity. The perceived gray scale level of a certain pixel is It is said that the bell is not linearly related to the ratio of black and white areas within it. Additional criteria were developed based on the facts. One of the implications of this is that The gray scale level of a pixel whose degree is 111 degrees from the maximum pixel density is the size of the bell. As a result, the highest density of gray scale level i.e. 1.8 The jump in density from to the next highest density of the gray level, that is, D*ax-1, is small. This means that it must be done. Finally, the pixel size, the bell size, The selection of the configuration pattern of the The number of bells, i.e. the smallest detectable shade, decreases rapidly with spatial frequency This is done in light of the fact that Therefore, at the limit of the resolution of the eye, black and It is necessary to represent only white.

According to the criteria mentioned above, we selected a high You can get copies of resolutions, e.g. 8'X10', 11'X14", 1 4. Pixel capacity for commonly available size copy pages such as “X17” It was determined that the visibility problem was resolved.

Furthermore, considerations regarding copying speeds suggest that a "print" pixel of approximately 90 μm x 90 μm will also be written in the preferred embodiment.

Early attempts to make copies using "print" pixels of approximately 90 μm x 90 μm This entailed the use of three laser beams. Each of them is 30μ on the medium A bell with a spot size of m x 3 μm was provided. However, the above theory As shown, such a configuration only gives a linear transfer increase of 91, which may give an inappropriate number of grayscale levels for some applications. was discovered. In fact, to get a better number of grayscale levels, you can use a much larger number. A large number of transmission increments is required. According to the invention, the large transmission increase number By pulse width modulation of the drive signal for the laser source, in this example, the drive signal for the laser source. , which produces a bell of variable size.

According to the present invention, a pixel is "drawn" using a predetermined area modulation pattern of Bell. A part of the bell modulates a given area of a given intensity level in the original image, or or correspond to a predetermined intensity level calculated by the printing machine.

In this context, the word "painted" means that the pixels of the heat-sensitive medium are exposed to laser radiation. means exposure to the beam. In the preferred embodiment of the invention, the pixels are approximately 60μ A brush with an area of m x 60 μm or 90 μm x 90 μm is selected, and The laser radiation beam used to "draw" the pixel using the It consists of a beam of laser radiation. As shown in FIG. Each of the first three radiation beams 200, 210, and 220 is spotted onto the medium. The smallest mark on the media is approximately 30 μm x 3 μm. This is an approximately equal area. Beams 200-220 are staggered and 25 The "brush" numbered 0 - the brush has 1.5 pixels of 60 μm x 60 μm or 90 μm It covers one m×90 μm pixel. As already discussed, the beam The selection of sizes for 200.210 and 220 is based on the above criteria and smaller dimensions. The complexity and expense required to obtain a smaller size bell, and the hard cost required to obtain a smaller size bell. The additional printing time required to produce the This was determined by factors such as additional expenses and printing time.

In addition, as shown in FIG. 1, in addition to the beams 200-220, the "brush" 250 is A fourth radiation beam consists of beam 230. Beam 230 The minimum trace on the medium is approximately equal to 5 μm x 3 μm. In addition, beam 230 passes roughly through the center of beam 210. They are aligned across the line.

As mentioned above, in this preferred embodiment, each of the beams 200-230 is It has a minimum needle width of about 3 μm, ie the distance from the top to the bottom of the trace. But long According to the invention, the stylus width is determined by each of the four beams, i.e. beams 200-230. It is variable for . To change the width of the casting, the width of the casting can be changed by When colliding the beam onto the medium! Just change ii. collide the beam with the medium To vary the amount of time each laser beam is used, the preferred embodiment pulse width modulates each laser beam to The width is the thickness of the laser beam, that is, approximately 30 μm or more to approximately 60.0 μm or It is possible to change the thickness in increments of 0.375 μm up to 900 μm. This lane The method of pulse width modulating the beam radiation is hereinafter referred to as slicing. g).

According to the present invention, the slicing can be performed using, for example, a 3 μm writing minimum writing time, or of the laser drive signal to turn on the laser for a longer time (10x*dt) This is achieved by modulating the writing frequency. Here, dt is the slice is the time to write and X is the desired number of slices. With slicing, This increases the effective number of bells within one pixel.

In certain embodiments of the invention, the selection of the slice size is based on an appropriate gray scale level. Balancing the need to obtain bell numbers and the complexity associated with obtaining very small slices Determined by matching. Very small slices are hardware This places enormous demands on both the media and the media. hardware becomes more complex On the other hand, the medium must be able to generate small spots. results and Thus, in the preferred embodiment, we selected slices of approximately 0.375 μm. but However, for those skilled in the art, the specific selection of the number of slices and the minimum and maximum width of the bell It should be clear that this is a matter of design and does not limit the scope of the invention. .

Below, the laser beams with different traces on the medium, each about 30μm×3μ Laser beam 200-220 with a minimum trace of m and a minimum trace of approximately 5 μm x 3 μm Advantageous results obtained by using a laser beam 230 having . Up When you print your copy on the media mentioned above, you will get the highest gray scale level for the media mentioned above. corresponds to a density value D□1 approximately equal to 30. 90μm x 90μm pixels and Using a minimal trace laser beam, i.e. a bell with dimensions of approximately 30 μm x 3 μm, the The next highest gray scale level in P is the density value Deaax approximately equal to 2. -1. Another way to understand this result is that a minimum trace of approximately 30 μm x 3 μm If we generate a copy using a bell with It is important to recognize that between 3 and 3, the concentration range will be set.

Of course, this is provided by medical imaging equipment that records vital information as density changes. is unacceptable for printing machines that must produce copies of images that Ru. Specifically, John M., Stern, Van Nostrand, and Reinho. Old Cumber---(John M, Sturge, Van No5tra nd and Re1nhold CoInpany) fEdited by , Neblett's Photography and Copying Handbook (Handbo) okof Photography and Reprography), No. As stated on pages 558-559 of the 7th edition, The most important photosensitive difference between it and true film is in shading. to an x-ray photograph In most cases, the changes in the concentration of the target are usually small, and increasing these differences will improve the diagnosis. X-ray film is designed to produce high shading as it adds to the value .

Radiographs usually contain densities ranging from 0.5 to over 3.0. Inspection is most effective on an illuminator with adjustable light intensity. 11. Non Printing radiographs on photographic paper unless always applied to a limited density range. Printing is not effective due to the narrow density range on the paper density scale . J As a result, the printing press can produce bells substantially smaller in size than 30μm x 3μm. You need to be able to write.

This performance is achieved in accordance with the present invention and as described above with respect to the preferred embodiment. This is provided by using the beam 230. In principle, laser beam 2 30 may be added to the "brush" 250 in any of several ways, but as shown in FIG. The arrangement shown in FIG. This provides a suitable arrangement for replacing the In the preferred embodiment, a small bell min. The size of Dams-1 is approximately 5 μm x 3 μm, and as a result, Dams-1 is 90 μm x 90 μm. It is approximately 2.7 for m pixels. the focus required to give a bell of a certain size Since the depth is inversely proportional to the square of the bell size, the depth is approximately 5 μm x 3 μm. This method provides a solution to the complexity and expense associated with obtaining bells of smaller dimensions. It makes sense.

Furthermore, as mentioned above, slicing is also performed by the fourth and smallest laser beam. applied to the written bell, as a result the number of gray scale levels increases dramatically, Less increase between gray level scales will be achieved.

Since the human eye is most sensitive to changes in transmission or reflection that occur at high concentrations, the gray scale Increasing the number of levels is most beneficial at high concentrations. Specifically, humans eyes are sensitive to relative changes in brightness as a function of dL/L (dL is the change in brightness , L is the average luminance). Therefore, when the concentration is high, that is, when L is small, the given The sensitivity to dL is high; on the other hand, when the concentration is low, that is, when L is large, the sensitivity for a given dL is high. Sensitivity to L is low. Accordingly, embodiments of the invention preferably Reduce the steps between gray scale levels at the high density end of the color scale . Furthermore, in accordance with this, the human eye is sensitive to the intensity that occurs in high-density areas of the gray scale. It is more sensitive to differences, so it is best to write the high density parts of the gray scale as accurately as possible. preferable. In a preferred embodiment of the invention, writing "white" on the media, as described above, Achieve this by. As mentioned above, in a preferred embodiment, the media is unprinted or When unused, it is black. To make a copy, use a laser beam of 200-230 sticks the copy-forming material on the media to the web surface through the use of radiation from necessarily entails that. Then, when the coating is removed, the exposed area is and the unexposed areas remain in the coating to form a hard copy. The hard copy is , the laser beam 200- to indicate the area where the black on the final copy will be removed. 230, making the hardcopy formation a process of "writing white". call. As can be seen from the above, a laser beam that generates a small bell can be used to achieve high concentration. This is advantageous because it gives grayscale levels that correspond to degrees. This advantage is , the specification accuracy of high concentration grayscale level is limited to a single laser beam, i.e., a small The fact that it depends on the positioning of the laser beam 230 which serves to write the small bell It can be obtained from When writing "black" on the medium, the laser beam 200-23 0, some, if not all, interactions lead to high concentrations of grayscale levels. bells are written, increasing the possibility of placement errors. As a result, “white” a level of accuracy comparable to that obtained by printing presses that utilize the process of To achieve this, printing machines must be more complex and expensive. This is as mentioned above Therefore, the difference in intensity is more easily detected in the high concentration part of the gray scale level. This is because medical images are generally darker than photographs. Despite the above , the present invention is not limited to the "write white" embodiment; the present invention is not limited to the "write black" embodiment. It should be understood that these examples also include examples.

In a preferred embodiment of the invention, a bell is used to "draw" a 90 μm x 90 μm printed pixel. The composition pattern is designed to suit several purposes needed for high-quality repeatable mapping. , designed. Creating a Bell Configuration Pattern for the “Write White” Preferred Embodiment The first objective is that in most medical images, the most important information is in the darker regions of the image. area, so for higher density grayscale levels, the area modulation within the pixel The goal is to minimize changes as much as possible.

In addition, the second purpose of creating a bell configuration pattern is to improve the image quality in the medium. The aim is to minimize bridging effects. Bridging refers to the above-mentioned media, This occurs even when the coating is removed, and the exposed material is laid out in close rows. material over the coatings and fills in the unexposed material between them. It's a phenomenon that draws you in. As easily recognized, bridging is This results in variations in density and therefore poor quality copies.

Bridging is a bell configuration pattern that preserves the shortest distance between clusters of exposed material. This can be prevented by using turns. For example, bridging The probability that two clusters of exposed material will bridge is approximately lO With a minimum unexposed distance between clusters of μm to 12 μm, it is significantly reduced. It was judged.

2A-2T show various 90 μm x 90 μm pixels according to a preferred embodiment of the present invention. Fig. 4 shows various bell configuration patterns for gray scale levels of . child These figures are best understood when viewed in conjunction with Table 1 (see page 57). It will be understood.

The grids in Figures 2A to 2T represent one 90μm x 90μm pixel in three columns. Each line consists of 30 lines. The first row of bells has a wide laser 3 The bells of the second or middle row are "drawn" by the wide or narrow laser l. Furthermore, the third or last row of bells is "drawn" by a wide laser 4. It was “drawn” by User 2. The coordinates of a particular bell in the grid are For numbers from 0 to 29, for columns, the laser "draws" that bell. Indicated by number. When looking at the 2T diagram from No. 28, we draw white. ” The “negation” of the medium, i.e. the white areas in the figure are the areas that were not exposed and the black areas are the areas that were not exposed. We must keep in mind that we are looking at something that is a "drawn" area. do not have. Therefore, the hardcopy will be the inverse of these figures. For example, ``Second A[ J represents the “negation” of the medium that was not fully exposed, resulting in the darkest represents a pixel with a high gray scale level.

In obtaining the bell configuration pattern for the preferred embodiment according to the criteria described above, we divided the bell configuration pattern into groups 8 to J, and we further divided the bell configuration pattern into groups 8 to J. I specified a certain ``drawing'' rule for the screen. This rule is shown in Table 1. , illustrated in FIGS. 2B to 2T. In particular, the pairs from Figures 2B to 2T The diagram below shows the bell configuration pattern at the beginning of the group and the bell configuration pattern at the end. are shown respectively. Specifically, with reference to Table 1, The shaded columns mean the bell configuration patterns in species groups A-J; The column titled ``Start of raster position'' specifies the grid coordinates of the first raster position in the group. It is a row and laser applied to a bell in a bell configuration pattern, and it is called "slice". The column entitled ``Range of cluster sizes in'' shows the range of cluster sizes within the group. For each of the lasers used to generate the constituent patterns, It gives the smallest and largest number. Table 1 and Figure 2B show that in group A The first bell configuration pattern is "drawn" by laser 4 starting from row 5 with 6 It shows that it consists of slices. In addition, Table 1 and Figure 2C show that group A The last bell configuration pattern in is "drawn" by laser 4 starting at row 5. It shows that it consists of 200 slices. Table 1 and Figure 2D show the group The first bell configuration pattern in B is ``drawn'' by laser 4 starting from row 5. A total of 110 slices and 12 slices drawn starting from J row O by laser 3. It shows that it consists of slices of . Furthermore, Table 1 and Figure 2E show that Group B The last bell configuration pattern in is 'drawn' by laser 4 starting from line 5. 200 slices and 12 slices starting from row O that are “drawn” by laser 3. It shows that it consists of slices. Table 1 and Figure 2F show the results for Group C. The first bell configuration pattern is "drawn" by laser 4 starting at row 5 at 110 slices and 12 slices "drawn" by laser 3 starting from row O and 12 slices drawn by laser 2 starting from line 15. It is shown that. Furthermore, Table 1 and Figure 2G show that the last bell in Group C The constituent pattern is 200 slides "drawn" by laser 4 starting from row 5. 12 slices “drawn” by laser 3 starting at row 5 and 2 indicates that each line drawn consists of 12 slices starting from line 15. are doing. The remaining items in Figures 2B-2T can be understood in the same way with reference to Table 1. I can do it.

Groups F-J, corresponding to lower densities, do not use small lasers 4; Please be careful. However, as mentioned above, human vision responds logarithmically. This means that even if there is a large difference in transmission or reflection in a low concentration region, it is still visible to the human eye. This is not a drawback since it means that you can hardly see it.

As can be easily recognized from the above, Figures 2A-2T and Table 1 show, for example, 256 The bell configuration pattern used to provide grayscale levels of It is something that Therefore, in reality, the values given in Figures 2A-2T and Table 1 An appropriate subset of the various bell configuration patterns for use in a specific case is: Depends on the specific demands of that specific case, and the appropriate subcent for that is the desired is selected to approximate the specific tone scale of . However, one To select a bell configuration pattern among the various possibilities in the group of Methodology may also be considered. First, the first bell configuration pattern for a group ``draw'' until reaching the last bell configuration pattern of the group. The amount of area that can be combed is determined for each laser. Next, the first bell configuration putter The maximum number of bell configuration patterns that can be "drawn" from that group other than the Initially, as obtained by "drawing" using a laser with an area of Select. However, the selected laser will not be able to obtain the selected bell configuration pattern. Since the amount of J area drawn for that laser decreases. 3. The amount of area that can be drawn with the first laser is larger than the area that can be drawn with the other lasers. These two lasers alternately “draw” the bell configuration pattern when Select a turn.

The laser source used to provide the beam for writing small bells is It may be similar to that used to provide a beam for writing a file, but its radiation Line power is suppressed using appropriately sized mirrors. Also, the light emitting area is smaller. You can also use a laser.

FIG. 3 shows an inventive printing machine that produces a hard copy of an image 50 on a medium 205. A block diagram of 10 is shown. As shown in FIG. 3, the printing press 10 (a1 image image scanning and acquisition module for acquiring image data corresponding to 50 in electronic form; image data obtained by the b1 image scanning and acquisition module 100; (c) (i) image frame storage unit 110 for storing data; The image data stored in section 110 is processed in a manner described in detail below, and (ii ) The processed image data and other information described in detail below are transferred to other parts of the printing press 10. In other embodiments, (iii) input information from the user is transferred to System controller 115, (d 1 image data from the image frame storage unit 110 and the system controller 11 5 control information, and in response to the control information to the laser module 750. a pixel generator 700 that generates an output; In response, a laser is used to generate a hard copy of image 50 on media 205. The laser module 75o1 is equipped with a laser 195.

Image scanning and acquisition module 100 is well known to those skilled in the art and to obtain image data in analog or digital form from image 5o and update it. and, if necessary, convert the acquired image data into digital form. picture Embodiments of image scanning and acquisition modules 100 are well known to those skilled in the art, and include For example, (al) scan the image 5o using radiation output from, for example, a CRT, (b) reflected from the image 50 and/or in a manner also well known to those skilled in the art. , measure the amount of radiation transmitted by the image 5° using a photodetector, and further ( C) This is also a method well known to those skilled in the art, e.g. analog/digital converter Create a digital image, e.g. from a photodetector, by sending the output through the It is equipped with a device that converts it into data. Also, image scanning and acquisition module +0 0 may be a CCD scanner. In the examples described below, image scanning is used for illustrative purposes. The digital image data output from the scan and acquisition module 100 each contains 256 frames. Assume that it consists of 8-bit data corresponding to the gray scale of the step. It is not limited to this. Furthermore, this is also for illustrative purposes and is limiting. However, each 8-bit image data is reflected from a predetermined area of the image 50. or the intensity of radiation transmitted through a predetermined area of the image 50. In addition, image scanning and output from the acquisition module 100, and of the system controller 115. The image data applied as input to the image frame store 110 under the control is e.g. For example, it can be similarly read out from storage media such as video tapes and optical discs. This will be obvious to those skilled in the art. In addition to this, digital image data can also be Occurs in remote locations and uses a local area network (LAN) or small computer to the image frame storage unit 110 via the system interface (SC3I) etc. Transfer is also possible. convert images to certain digital or analog formers It accepts image information in any format without having to store it in a It will be understood that it is also within the contemplation of the present invention.

Each image data output from the image scanning and acquisition module 100 consists of one pixel. may be displayed in an area larger than, equal to, or smaller than the dimensions of Wear.

For example, certain selections may be made based on format versus content. "Four The word "matte" means, for example, the aspect ratio of the copy, and the word "content" means the resolution and gradation of the copy. As shown in Figure 3, there is In an embodiment, such selection is made by the system controller through user input. 115 can also be entered. However, in the examples described below, the example For illustration purposes only, the area corresponding to the image data on image 50 is typically smaller than one pixel. large, and therefore have low spatial resolution, but are not limited to this. do not have. As a result, in the hard copy produced by the imaginary printing press 10 , more pixels than the area in image 50. Additionally, for illustrative purposes only, Media 2 05 is fixed to the outer surface of a drum (not shown), which is known to those skilled in the art. As is well known, it is cylindrical in shape. Typical of such implementations is is fixed to the drum, as is also well known to those skilled in the art. As the media rotates, the output from laser 195 in laser module 750 is The radiation impinges on the medium 205 along the line. Furthermore, laser module 750 The radiation output from the laser 195 is moved in a direction transverse to the direction of the line. Then, a sufficient number of lines are formed on the medium 205 so that the image 50071-copy is obtained on the medium 205. Furthermore, a one-page hardcopy output may be Images may also be included, such as on an 8 x 10 inch hard copy. The pixel size, pixel aspect ratio, e.g. per page in the 8 inch direction The actual number of lines and the actual number of pixels per page in the 10 inch direction are gram, and embodiments of the present invention are capable of controlling any of these parameters. It is not limited to one specific set.

The image frame store 110 is configured to store images 50 or a number of such images. is well known to those skilled in the art, and serves as a temporary storage for image data. Any device may be used as long as it can be used. The system controller 115 In a manner well known to those skilled in the art, "pages" are stored in image frame storage 110. Configure and format. The "page" is stored as a hard copy on the medium 205. It is something that is generated. As a result, a "page" is a single image such as image 50. It may be composed of , or it may be composed of many images such as image 50. stomach.

The system controller then directs the pixel generator 700, preferably to the VME bus 6 95, the configuration data used by the pixel generator 700 to perform its functions. Transfer the following as data: (a) For example: (i) Number of lines per page , (ii) Number of pixels per line in the drum rotation direction, (iii) Drum (iv) the aspect ratio of the pixel, etc. Values of certain programmable parameters of pixel generator 700, (detailed below) for generating signals for driving laser module 750 in the manner described in Reference table data used, and (C) forming part of pixel generator 700 Software used by a digital signal processor (DSP). certain implementation In the example such data and software are stored before each hardcopy image is created. However, in other embodiments, the related data and the software, or any part thereof, to different parts of the hardcopy. We may not transfer any such data or software, even if necessary. It will be obvious to those skilled in the art that it can also be used.

As shown in FIG. 4, the pixel generator 700 consists of the following components. ( bl　V　M　E interface + 19゜VME interface 119 is It receives input via the VME bus 695 and connects the internal circuitry of the pixel generator 700 and the VM Provides an interface to the E-bus 695. (blDsP120゜DS P120 receives parameter data, software, and image data (this data and information is sent to the system controller 11 5 via the VME bus 695 to the VME interface 119, and the VM (Relayed to DSP 120 by E interface 119), (C)D SP memory 121. The DSP memory 121 includes (i) the system controller 115; receives parameter data and software from (this data and information is From the system controller 115 to the VME interface via the VME bus 695. interface 119 and is sent to DSP 120 by VME interface 119. relayed and finally relayed by DSP 120 to DSP 121), and (ii) Transfer parameter data and software to DSP 120. (d ) INX memory 130゜INX memory 130 is used for (i) system control image data from the controller 115 (this image data is sent to the system controller 115). controller 115 to VME interface 119 via VME bus 695. is relayed to the DSPI 20 by the VME interface 119, and finally (relayed by DSP 120 to INXI 25), and (ii) DSP 1 In response to commands from the DSP 20, the image data is transferred to the DSP 20. (el Out buffer 140° The out buffer 140 receives image data from the DSP 120. , receives addressing information from (100) pixel dimension 163, and ( iii) forwarding the image data to LUT processor 170; ) Pixel size 163 ゜Pixel size +63 is (1) parameter data (for example, line per page number, pixels per line in the direction of drum rotation, number of pixels per line in the direction of drum rotation number of bells per pixel) from the system controller 115 (this data is the system controller] 15 to the VME interface via the VME695. by the VME interface 119 to the pixel size 16 3), and (11) pixel address information to the out buffer 140, The bell address information is then transferred to the LUT processor 170. (gl reference table LUT processor 170 (LUT processor 170 is not limited to 2 memories, but only 1 memory or 2 It will be obvious to those skilled in the art that it can also be configured with the above memories).

Each memory has an intensity level for use in digital domain modulation printing on media 205. It is equipped with mapping for the bell configuration pattern of . LUT processor 170 (i) receives mapping data (this data) from the system controller 115; The VME data is sent from the system controller 115 to the VME input 97z-space 119. via bus 695 and by VME interface 119. (relayed to processor 170), (ii) intensity level from out buffer 140 receives bell input, and (iii) bell address information from pixel dimension 163. . (Inc.) Multiplexer and delay 180° Multiplexer and delay 180 is ( i) from LUT processor 170 containing laser drive information in 16-bit words; Receive input. This 16-bit word contains four lasers included in laser 195. It consists of four 4-bit values for each.

and (ii) two 16s from LUTO and LUTI of LUT processor 170. The mapping information in the bitword can be adjusted to suit the specifics of the laser 195. DPS, including the information used to determine how to convert it into Receives input from 120. (i) Slice 190° Slice 190 is ( i) Receive input from PLL 185, (jl) multiplexer and delay +80, and (1st) this 16-bit input signal. is converted into a signal used to drive laser 195. (j) P’L L 185° PLL 185 is a phase-locked loop clock, (i) (11) synchronizes with the rotating drum; Outputs the clock. (k) When the drum rotation reaches the predetermined position Drum encoder 187° that receives signals from The operation of pixel generator 700 will be described in more detail below. system controller 115 is a portion of the image stored in the formatted image frame storage section ]]0. Get data corresponding to minutes. The system controller 115 The 8-bit data is sent to the pixel generator 700 in real time via the VME 695. Transfer by system.

The term "real time" refers to, for example, a format in the image frame storage unit 110. Data corresponding to a portion, such as one or two lines of a matted image, is This means that each rotation of the drum is transferred to the pixel generator 700 and processed. Ingredients Physically, it corresponds to an 8 x 10 inch copy printed using 60μ x 60μ pixels. Thus, the maximum number of 8-bit pixels transferred per line in the preferred embodiment is 4096. It is.

An 8-bit image is transferred from the system controller 115 to the pixel generator 700. Raw data passes through the VME bus 695 and via the VME interface 119. transferred and applied as an input to the digital signal processor 120 (DSPI20). It will be done. DSP] 20 then transfers this data to INX memory 125. I NX memory 125 is a device known to those skilled in the art for storing digitized image data. is a well-known device. For example, the INX memory 125 has random access It may be a memory. The INX memory 125 is used for processing by the DSP. Used as input buffer memory to store waiting image data It is. The INX memory 125 may hold image data for several lines. Good, but typically not one that holds an entire "page".

At an appropriate time, the DSP 120 obtains image data from the INX memory 125 and processes it. and stores the processed data in the out buffer 140. DSP120 Examples are well known to those skilled in the art. For example, preferred embodiments of the invention In this case, the DSP 120 is a Motorola 56001 digital signal processor.

The DSP 120 has access to a DSP program memory 121, such as a RAM memory element. input digitized image data required to create a hard copy. Convert to a format compatible with the desired output format, i.e. Convert image data to "print J data" of "pixel size" and/or "clear" DSPI20 to improve the image quality of hard copies through the process of Get software to guide you. For example, for purposes of illustration, in one embodiment of the invention: DSP 120 processes digital image data by using two one-dimensional interpolation steps. Two-dimensional interpolation is performed on the data, but it is not limited to this. specifically The DSP 120 (acquired by the a1 image scanning and acquisition module 100) The design of the “interpolated” line on image 50 between the two actual lines a first one-dimensional interpolation step to obtain digitized image data, and (bl actual or "interpolation" between the input data points for each interpolated scanline. a second one-dimensional interpolation step that generates digitized image data for the Execute the step. In particular, such interpolation steps are well known to those skilled in the art. may include, but is not limited to, the following steps: . These include nearest neighbor interpolation, bilinear interpolation, 3D convolution, etc. Furthermore, above digitized image data, including any interpolated digitized image data, as described above. The image data may be sharpened using methods known to those skilled in the art. Furthermore, the original Particular embodiments of brightness include applying different interpolation methods to different portions of image 50. Can be done. And furthermore, as already indicated, the DSP program memory 121 The software stored in the system is transferred there from the system controller 115. It is what was done. (a) In some embodiments, different images may Before printing each page to allow the image algorithm to use it. (In other embodiments, the software can be loaded with The software can be loaded prior to printing the portion of the (C) In yet another embodiment, the software is installed all at once when the system is powered on. You should be careful about loading it.

In this embodiment, the output of the image processing obtained by the DSP 120 is the processed image. Contains an 8-bit number corresponding to the plain gray level. However, the present invention It will be appreciated that the use of 8-bit intensity levels is not limited.

The image processing output is stored in out buffer 140. The examples described here are , transfers the image data to the pixel generator 700 and stores it in the INX memory 125. , and entails performing image processing on image data in real time. , which is advantageous because it reduces the memory cost of the inventive printing press.

In the preferred embodiment, two output lines are produced on media 205 during one rotation of the drum. The image data required for creation is input to the pixel generator 700. 1 output line In is defined to extend in the direction of rotation. During the next rotation of the drum, two more The lines of the book are transferred and the two lines transferred during the previous rotation are image processed. and output to the out buffer 140. On the third rotation, two more lines The lines from the previous rotation are processed, memorized, and then used for the second rotation. The lines processed during rotation are output and printed on a rotating drum.

This continues until the entire "page" is printed.

However, the image requires two lines per rotation for each output line. There are some things that don't. For interpolation, the transfer of the input line to the pixel generator 700 is It may be less frequent.

As mentioned above, the image processing DSP 120 produces an 8-bit digitized output image data. The data is transferred to the Aratono buffer 140 for storage. Out buffer 1 40 for storing digitized image data, well known to those skilled in the art. It is a device for For example, in a preferred embodiment of the invention, outbuffer 140 is A dual port buffer, e.g. a dual port ram, with the first speed Read/write is performed by the DSP 120 through one port, and the second Capable of reading through the LUT processor 170 through the port It is. This is a speed proportional to the speed at which the image should be written and the rotational speed of the drum. , allowing data to be accessed by the remainder of the output path of pixel generator 700. do. Additionally, in a preferred embodiment, outbuffer 140 may contain one or two pixels. The DSP 120 can also output lines from different parts of the line. 4 pixels per time are stored in it. However, Aratono<5. F+ 40 need not be dual-port RAM, e.g. first-in first-out memory. Good too.

According to the present invention, LUT processor 170 outputs pixels from outbuffer 140. Data in the form of pixel values, and bell address information, hereinafter referred to as row address, in pixel form. From the dimension 163, remove the receiver. LUT processor 170 uses this input to Bell configuration pattern information is searched from a number of predetermined bell configuration patterns. Au pixel data from buffer 140 (buffer is selected by DSP 120) ) executes the LUT process in response to address information received from pixel dimension 163. is transferred to processor 170.

Next, the method by which LUT processor 170 transforms the pixel data, i.e., the area modulation image The raw digitized output pixel data is obtained from a number of predetermined bell configuration patterns. The method of converting the information into the obtained bell information will be explained in more detail.

However, in this regard, the configuration of LUT processor 170 will be described in more detail. I will post it. Specifically, LUT processor 170 uses lookup table memory LUTO and LUTI. In a preferred embodiment of the invention, each memory has a strength level , that is, the same Contains reference tables. LUT'O and LUTI are well known to those skilled in the art. It consists of a memory storage element of the type described, well known to those skilled in the art. be. The bell configuration pattern corresponding to each possible intensity level data is e.g. , determined in advance from the results of psychophysical tests.

However, the invention is not limited to the use of one particular mapping. stomach. Specifically, in some embodiments of the invention, specific intensity levels and bases may be used. By changing the initial configuration of the printing press 10, or by storing several mapping sets, and how to use the deviations of a given tone scale mapping to create a particular copy. By receiving manual input from the user, as shown in Figure 3, Therefore, it is within the scope of the present invention to make changes. For example, you by setting an indicator or pressing a button, or by the user setting an indicator or pressing a button. receives manual input by providing input to a user-interactive system. You can take it. For example, for the purpose of adjusting brightness and/or shading, The files can also be varied for use in specific applications.

The output from LUT processor 170 is output to laser 195 of laser module 750. This is data used to control the behavior of Specifically, preferred implementation of the present invention In the example, LUT processor 170 may be configured to use four lasers included in laser 195. 16 bits of 4 hexadecimal coded bits for each give a number.

For the purposes of this discussion, and in the following description, we will refer to the laser 195 laser Assuming that 1, 2 and 3 are capable of supplying a bell of approximately 30 μm x 30 μm. , and laser 4 of laser 195 has the ability to supply a bell of approximately 5 μm x 3 μm. Specify as something. The four hex-coded bits are sliced using the slicing method described above. while the slicing method is encoded to perform the slicing method on the medium 205. The laser can be used to irradiate an area containing a fraction of the size of one bell. Split the time to activate.

Multiplexer and delay 180 can be implemented using commercially available soft registers or With programmable gate arrays, manufacturing can do. In particular, the multiplexer and delay 180 is the LUT processor The above 16-bit number from 170 and 60 μm x 60 μm or 90 μm x Receives information from DSP l20 indicating whether 90μm pixels are printed. Take it. This information will be explained in detail later, but select 4 bits per laser. used for. This 4 bits per laser is used as a signal to drive lasers 1-4. Used for further development. 4 bits for specific ones of lasers 1-4 The signals corresponding to the delayed for.

The relative delays of the various laser drive signals can be understood as follows. As mentioned above, The preferred embodiment of the creative printing press IO uses four lasers in laser 195 to A "brush" for printing hard copy lines is provided on the body 205. . Accordingly, e.g. between beam edges due to diffraction and beam irregularities To prevent interference from causing inadvertent printing errors (this irregularity (often occurs at the edge of the beam), the laser beam forming the “brush” is physically one Avoid placing them side by side on a line. This beam irregularity causes the focused Gauss This is due to the fact that the laser beam gradually decreases from its maximum at the center of the beam. This is due to this.

Therefore, the focused laser beam cannot produce a spot of uniform intensity. , some areas of the media may be far below or far below its exposure threshold. It becomes expensive. To avoid this problem at the edges, scan the laser It is a spatial shift in the direction. Therefore, the firing of these lasers is delayed from each other. so that when the bells generated by lasers 1.2.3 and 4 expose the medium, Do not make them consistent with each other. In this way, multiplex The laser and delay 180 may be applied at the time the laser fires to form the "brush". and add or subtract predetermined delays to compensate for their spatial offset. for example , in the preferred embodiment, lasers 2 and 3 are delayed by 64μ with respect to laser l. , laser 4 is delayed by 128μ with respect to laser l.

A multiplexer and delay 180 switches the 4-bit number for each of the four lasers. Transmit to Rice 190. In the preferred embodiment, each 4-bit number has a number from 7 to 15. A 4-bit hexadecimal number that determines how many slices of the bell the laser should be energized over. The bell has a maximum length of 3 μm in the direction of rotation of the drum.

Slice 190 may include commercially available array logic or programmable graphics. can be manufactured from sheet arrays by methods readily understood by those skilled in the art. Special In addition, slice 190 divides the input from multiplexer and delay 180 into into four digital signals and send them to the laser module 75o. Applied as an input to the laser driver. These digital signals are or off, they are high or low, respectively.

The phase lock loop 185 (PPLI 85) detects the rotation of the drum and Receives input from drum encoder 187 which generates a signal input to rice 190 The output from the slice 190 is synchronized with the rotating drum.

In a preferred embodiment, one tick is 2150 rpm, or at a suitable speed of 0.375 μm.

In response to the digital signal output from slice 190, laser module 75 The laser driver in 0 generates a high current drive signal and uses it to drive the laser 195. Apply to find out. In response to this drive signal, the laser 195 is timed. emit radiation beams that impinge on the medium 205 and deposit thereon a copy of the image 50. generate.

Of course, the optical head (not shown) within the laser module 750 that holds the laser 195 is When moving the line in the transverse direction, the laser moves in the direction transverse to the line direction on the medium 205. Traversing the radiation output from the laser 195 creates more lines on the media 205. It will be obvious to those skilled in the art that printing is possible. Examples of suitable optical heads are e.g. , filed on the same day as this case and assigned together, named "Optical Head for Printing Machines" No. 7,584 (our Case No. 7584). In addition, The lasers are activated only when their beams impinge on the medium 205; When the drum collides with, for example, a drum clamp, it is not activated. In addition, creation The printing press 10 is well known to those skilled in the art, but to facilitate understanding of the present invention. It will be obvious to those skilled in the art that the device may include additional equipment omitted in the above. for example, The creative printing press 10 includes, but is not limited to, the following types of modules: Do not mean. They consist of a drum drive, drum positioning synchronization means, and a laser beam. These include a dynamic focusing device, a medium transport unit, and the like.

Next, we apply the data stored in the out buffer 140 to the LUT process. A method of applying the signal as an input to the laser 170 to generate a laser drive signal will be described. Au The 8-bit processed data in the buffer 140 is stored above the LUTO and LUTI. output as a position address. Adding 8-bit data in out buffer 140 The response is determined by the signal transferred there from the pixel dimension 163, and the outbound This is the address of the dual port ram of the buffer 140 on the printer side. this address Update the signal at pixel rate. For example, for a pixel of 60 μm x 60 μm, The address is updated every 60 μm, whereas for a 60 μm x 80 μm pixel, , the address is updated every 80 μm. Lower part of LUTO and LUTI addresses The row address is the pixel size applied as input to the LUT processor 170. generated in response to the output signal from method 163. The row address counter is Count from 0 to 29 at the start and repeat at a rate corresponding to 3 μm bells.

In particular embodiments, pixel and bell rates can be determined from the following information:

That is, the page length, e.g. 10 inches, the pixel size, e.g. 60 μm x 60 These are the size of the bell, such as μm, 90 μm×90 μm, and the rotation speed of the drum. example For example, the per rate is equal to (slice clock)/8 and the rotation of the drum is In an example where the speed is 2400 rpm and the bell is 3 μm, the per rate is 30 MHz. /8. Furthermore, the pixel rate is (per rate)/(number of bells in one pixel). Become. Finally, for a 60 μm x 60 μm pixel, there are 20 pels/pixel and 9 For a 0 μm x 90 μm pixel, this is 30 pels/pixel.

Next, we refer to FIGS. 5 and 6 to extract the data from the LUT processor 170. I will explain in detail how to extract it. Figure 5 shows how LUTO and The data stored in the LUTI and the data stored in the laser module 750 are This helps indicate which signals provide the bell information used to drive the laser 195. It is something that Specifically, FIG. 5 shows mapping for a 90 μm x 90 μm pixel. The size of the 60 μm x 60 μm pixel and other pixels can be similarly given using Based on our discovery that a 60μm x 60μm image can be Extract data to provide bell information for pixel and 90μm x 90μm pixel. It helps to show the water.

In particular, we first consider the case of a 90 μm×90 μm pixel. Preferred embodiments of the invention As described above with respect to FIG. The brush consists of laser 3, lasers 1 and 4, and laser 2. laser 1.2 and 3 each trace 30 along the direction indicated by arrow 2000 .mu.m, and the trace of the laser 4 is 5 .mu.m. Therefore, lasers 1-4 are excited. and strikes the medium 205 along the path between lines 1103 and 1004; These "drawings" are made with brushstrokes with a width of 90 μm. Furthermore, as shown in Fig. As shown, the distance between arrows 2000 and 2002 is 90 μm. therefore , there are 30 bells in a 90μm x 90μm pixel, and the border line is a line. 1003 and 1004, whose lines are indicated by arrows 2000 and 2002. It is.

The data stored in LUTO and LUTI are the same, and these data This corresponds to the aforementioned 90 μm×90 μm pixel. As a result, 90 μm x 90 μm It is only necessary to search the data stored in the LUTO for one pixel.

Figure 6 shows a data matrix corresponding to a 90μm x 90μm pixel. It is. Rows 0-29 correspond to the bells for laser l-4, and each row, i.e. rows 0- 29 has a 4-bit hex coded value for each of lasers 1-4. Contains a 6-bit number.

To retrieve this data, LUT processor 170 requires two pieces of information: raw intensity level (in the preferred embodiment this is an 8-bit number between 0 and 2525) ) and the bell number (in this example, the bell number is indicated by the arrow 2000 on the medium 205 0 and 2002, corresponding to the bell drawn when the laser beam collides between 29) must be supplied.

In response to this information, LUT processor 170 extracts the 16-bit number from the LUTO. Search for. Here bits 0-3 are used for laser 2 and bits 4-7 is used for laser I, bits 8-11 are used for laser 3, and Bits +2-15 are used for laser 4. Of course, this bit selection Those skilled in the art will understand that is optional and can be changed in other embodiments. Will. For example, change this bit selection in software or cable. Good too.

to the LUT processor 170 corresponding to the intensity level of the pixel and the row address of the bell. inputs are obtained from out buffer 140 and pixel size 163, respectively. pixel Dimension 163 has three registers each containing the following information:

They are the number of pels/pixels, the number of pixels/lines, and the number of lines/pages. . Thus, pixel size]63 is the number corresponding to the position of the pixel within the line to be printed. It is transmitted to the out buffer 140. Out buffer 140 uses this number to The pixel stored here and corresponding to the line is addressed. out buffer 140 corresponds to the intensity level of the pixel and is printed as input to the LUT processor 170. The value to be added is retrieved from its memory. At the same time, the pixel size 163 is Apply the value of the row counter, cycling between 0 and 29, as input to processor 170 do.

For ease of introduction, an out buffer 140 is stored in its memory. The pixel size 163 cycles between 0 and 29 for each such pixel. As it is turned, one line of data is extracted and the laser module 750 is used to fire the laser 195 inside.

Next, proceed to the case of a pixel of 608 m x 60 μm. In this case, two facts It's getting complicated. First, in order to utilize all four lasers, 608mX A 60μm pixel requires 1.5 such pixels to be printed simultaneously Ru. Second, due to system online constraints, one reference table memory You don't have enough time to search for the data you need.

Referring to FIG. 5, the LUT processor 170 performs the necessary laser drive design as follows. pull out the data. First, lie: /1003 and 1005, and arrows 2000 and 20 Area indicated by A1, which becomes pixel 1 between 01 and line 1005, which becomes pixel 2. and 1006, and the area indicated by A2 between arrows 2000 and 2001, and Between lines 1006 and 1007 and arrows 2000 and 2001, which is pixel 3 Consider the region denoted by,A,. The pixels in the line of pixel I are from the LUTO Using the data obtained, it is drawn by laser 3 and lasers 1 and 4. picture Pixels in the line of laser 2 are identified by laser 2 and It is drawn by the laser 3. Furthermore, the pixels in the line of pixel 3 are Using the data obtained, lasers 1 and 4 and laser 2 are drawn. capacity A line of pixels, or line, is drawn across the page for easy recognition. The directions across the directions are alternately from LUTO and LUTI in various sequences, Obtain data to drive the laser.

In addition to the above, the "brush" includes laser 3, laser l and/or 4, and laser 2. Therefore, the brush simultaneously encompasses 1.5 pixels of 608 m x 60 μm. this Data that accomplishes the task is derived as follows.

(1) For pixels between lines 1003 and 1005 and arrows 2000 and 2001 The data of laser 3 and lasers 1 and 4 are set to intensity level A1 and row address 0-1. 9 to the LUT processor 170. There For each 16-bit number drawn from , bits 8-11 are for laser 3. bits 4-7 are for the laser, and bits 12 -15 is for laser 4. (2) Lines 1005 and 1004, and Laser 2 data for half of the pixels between arrows 2000 and 2001 is expressed as an intensity level. By supplying bell A2 and row addresses 0-19 to LUT processor 170. and obtain it from LUT 1. For each 16-bit number drawn from it, G-3 is used for laser 2. (3) Lines 1003 and 1005, and Data of laser 3 and lasers I and 4 for pixels between arrows 2001 and 2003 For the part between arrows 2001 and 2002, intensity level B1 and row arrow by providing addresses 20-29 to LUT processor 170, and For the part between arrows 2002 and 2003, intensity level B1 and row address 0-9 to the LUT processor 170.

For each 16-bit number drawn from it, bits 8-11 are for laser 3. bits 4-7 are for laser 1, and bit 1 2-15 is for laser 4; (4) Lines 1005 and 1004, and The laser 2 data for the half pixel between arrows 2001 and 2003 is For the part between 2001 and 2002, intensity level B2 and row address 20 -29 to LUT processor 170 and arrow 200 For the part between 2 and 2003, set intensity level B2 and row address O-9 to L. from the LUTI by feeding it to the UT processor 170. From there For each 16-bit number written out, bits 0-3 are used for laser 2. Ru. (5) Pixels between lines 1003 and 1005 and arrows 2003 and 2004 data of laser 3 and lasers l and 4 for intensity level C2 and row address 1 0-29 to the LUT processor 170. . For each 16-bit number drawn from it, bits 8-11 are of laser 3. bits 4-7 are for laser l, and bits 1 2-15 is for laser 4; (6) Lines 1005 and 1004, and The laser 2 data for the half pixel between arrows 2003 and 2004 is supplying level C2 and row addresses 10-29 to LUT processor 170; Therefore, it is obtained from LUTI. For each 16-bit number drawn from it, Cuts 0-3 are for laser 2.

Next, we laser the second half of the line of pixel 2 and the line of pixel 3. The method for obtaining drive data will be explained. (1) Lines 1004 and 1006 and arrows Laser 3 data for half pixels between 2000 and 2001 is converted to intensity level By supplying A2 and row addresses 0-19 to LUT processor 170, Obtained from LUTI. For each 16-bit number drawn from it, bits 8- 11 is used for laser 3. (2) Lines 1006 and 1007 and arrows Data of lasers 1 and 4 and laser 2 for pixels between marks 2000 and 2001 , intensity level A3 and row addresses 0-19 to LUT processor 170. is obtained from the LUTO by

For each 16-bit number drawn from it, bits 4-7 are for laser 1. , bits +2-15 are for laser 4, and bits +2-15 are for laser 4, and bits 0-3 is for laser 2. (3) Lines 1004 and 1006, and The data of laser 3 for half the pixels between arrows 2001 and 2003 is For the part between 001 and 2002, intensity level B2 and row address -20 -29 to LUT processor 170 and arrow 200 For the part between 2 and 2003, set intensity level B2 and row address 1)-9. from the LUTI by feeding it to the LUT processor 170. From there For each 16-bit number extracted, bits 8-11 are used for laser 3. It will be done. (4) Between lines 1006 and 1007 and arrows 2001 and 2003 The data of lasers 1 and 4 and laser 2 for pixels are indicated by arrows 2001 and 2002. For the part between, intensity level B3 and row addresses 20-29 are set in the LUT process. 170 and between arrows 2002 and 2003. For the section, intensity level B3 and row addresses 0-9 are sent to LUT processor 170. obtained from LUTO by supplying 16 bits each extracted from it , bits 4-7 are for laser l, bits 12-15 is for laser 4 and bits 0-3 are for laser 2. be. (5) The half between lines 1004 and 1006 and arrows 2003 and 2004 The data of laser 3 for the pixel of is obtained from the LUTI by feeding it to the LUT processor 170. Is that there? For each 16-bit number drawn from the I can stay. (6) Between lines 1006 and 1007 and arrows 2003 and 2004 The data of lasers 1 and 4 and laser 2 for the pixels in the intensity level C2 and the row address 10-29 to the LUT processor 170. get from For each 16-bit number drawn from it, bits 4-7 are the laser 1 and bits 12-15 are for laser 4. , and bits 0-3 are for laser 2.

A LUT processor 170 corresponding to the intensity level and row address, as described above. Inputs to are obtained from out buffer 140 and pixel size 163, respectively. deer However, in this case, instead of being continuous in one line of pixel intensity level data, Out buffer +40 should be continuous across two lines at the same time. Already This feeds the intensity level from one line to the LUTO, as shown in the intensity level from the other line. Bell is being supplied to LUTI. Specifically, as shown above, pixel 1 Apply the intensity levels from the pixels in the line to the LUTO, and apply the intensity levels from the pixels in the line to Apply the intensity level from to LUTI. Then, the line of pixel l and the line of pixel 2 After printing the first half of the in, set the intensity level from the pixel in the line of pixel 2 to L and apply the intensity level from the pixel in the line of pixel 3 to the LUTO is applied to the second half of the line of pixels 2 and the line of pixels 3.

Continue this alternating technique until all lines of the page have been applied.

In addition to the above, embodiments of the present invention also apply to situations that utilize pixel duplication and enlargement. You will understand what you can do.

For example, using repetition factors for lines and/or pixels, As explained in the example, it is possible to map one pixel to one output pixel. It is also possible to enlarge the image by an integer multiple in either direction, such as the minimum size.

In addition, as a special case, complex cases where each input pixel produces an integer number of output pixels Shading characters can be realized by using manufacturing coefficients. In this case, the intensity level is It is represented by the whole matrix, never by a part of the matrix. Change In addition, the pixel aspect ratio is adjusted using unequal pixel and line duplications to correct It is also possible to correct input pixels, output pixels, and/or both that are not square. child Various embodiments such as It can be obtained by programming.

In a preferred embodiment, mapping of pixel-to-bell configuration patterns is performed using a specific type of pine pin. It should be noted that the However, the present invention It should be noted that the use of example mappings is not limited. one In general, the present invention provides pixel-to-bell configuration pattern mapping, e.g. generated by, but not limited to, clustered threshold arrays. area modulation mapping, dither mapping with dispersed dots, rectangular or hexagonal Square array structure, bells used for lower grayscale levels are used for higher grayscale levels. Different maps, such as non-monotonic bell configuration patterns that do not need to be used at the scale level, This applies to embodiments such as a whole host of topping functions.

The present invention utilizes such changes in mapping pixel-to-bell configuration patterns. The embodiments of the present invention can be used to create matrices containing such mapping data in a manner that will be obvious to those skilled in the art. Manufacture the LUT Brose-Tusa 170 to extract the right data from the risks. It can be manufactured by

For example, if the DSP 120 has a pixel intensity that is stored in the out buffer 140, one of a number of write element printheads consisting of a laser 195. In an example of a printing press designed to print a large number of lines in a path, an outback Make the line inside F140 a double knot/sofa, and print one group of lines. You can also allow the next set of lines to be read into it while it is in there.

For example, in such an embodiment, pixel generator 700 may be configured to Initialized by the pixel intensity level to be printed and the number of bells in one pixel. be done.

Additionally, space is allocated for the buffer within the out buffer 140 and the out buffer initialize pointers to the current print and load buffers in the buffer 140; , set flags corresponding to these two states.

The first step in printing is to load the line into the bath. rotating door There is a signal PGactive that indicates the position of the ram. PG active is When the laser is active, i.e. prints a line and when the laser is active, i.e. prints a line. indicates whether the laser is on the clamp, ie, the laser is off.

During one rotation of the drum, the DSP 120 fills the buffer in the out buffer 140. However, when the laser is on the clamp, either the 60μm or 90μm pixel is From one or two lines of 8-pin pixels, depending on what is being printed. Start.

Writes from DSP 120 to out buffer 140 during the same rotation and during the previous rotation. One or two lines of 8-bit pixels are transferred from the out buffer 140 to the LU T170 and printed on the page. During the next rotation, DSPI 20 will The out buffer 140 fills the buffer used for the previous print and also fills the buffer used for the previous print. Output from the buffer filled by DSP 120 during the previous rotation.

In such an embodiment, to print a pixel, the pixel-to-bell mapping is 170. For example, for mapping The inputs are an intensity level, a column pointer, and a matrix corresponding to said intensity level. is a row pointer to the bell in a particular column and row of the file. Matori like this Methods for storing and retrieving messages from storage are well known to those skilled in the art. be.

Any modification of the invention, including additions, subtractions, deletions, and modifications of the disclosed preferred embodiments of the invention. Other embodiments will be apparent to those skilled in the art and are within the scope of the following claims.

Table 1 FIG, 2A FIG, 2B FIG, 2C FIG, 2D FIG, 2F FIG, 2F FIG, 2G FIG, 2H FIG, 2I FIG, 2J FIG, 2K FIG, 2L FIG, 2M FIG, 2N FIG. 20 FIG, 2P FIG. 20 FIG, 2R FIG, 2S FIG, 2T Ma 'fMt Buddha Takashi ←44- 44- international search report lal, ++1+++l Il+, l++Il++ jl+ ρCT/US 9 110687m international survey report

Claims (14)

[Claims] 1. To form a hardcopy image as multiple pixels on or across a medium. A printing device that provides a drive signal to an energy source whose output is used for printing purposes. means for receiving an input image signal representing at least a portion of the original image to be printed; In response to receiving the image signal, within one pixel consisting of subpixels called pels. generating at least one pixel signal representing at least one area modulation pattern of means for doing so, wherein the pixel area corresponds to the brightness of a predetermined portion of the original image; means and Modulate the pixel area using a pattern of pels as multiple substantially adjacent columns. an energy source responsive to the pixel signal; and at least one set of pel configuration parameters in response to the pixel signal. generating a turn signal and activating the energy source required within one pixel; and means for generating a pel pattern. 2. 3. The apparatus of claim 2, wherein at least two of the pel rows are transverse to the scanning direction. The measured magnitudes are different, and each is equal to the initial minimum magnitude measured in the scanning direction. The device having a sharpness. 3. 3. The apparatus of claim 2, wherein the driving means further comprises one slice called a slice. Increase their initial size by adding more vice pels to it said apparatus, wherein said apparatus is configured to increase the size of pels within said pel array; . 4. 2. The apparatus of claim 1, wherein the pel row has a predetermined width in a direction transverse to the scanning direction. said devices overlapping each other by an amount. 5. The apparatus of claim 1, wherein the radiation energy source is a radiation laser source. , said device. 6. 6. The apparatus of claim 5, wherein the laser source has a plurality of 1. The device comprising one laser source in each case. 7. As a plurality of pixels on or throughout the medium, the pixels are divided into subpixels called pels. A scanning print head for forming a hard copy image, comprising: The first one has a predetermined fixed length in the direction transverse to the scanning direction and has a minimum length in the scanning direction. a radiation source, further spatially offset in the scanning direction with respect to the first source; At least one piece that spatially overlaps with it by a predetermined amount in the transverse scanning direction. and another radiation source. 8. 8. The printhead of claim 7, wherein the radiation source comprises a laser. print head. 9. 9. The printhead of claim 8, wherein the laser is a phased array laser diode. There is said print head. 10. The printhead of claim 7 further comprises selecting the firing of the radiation sources relative to each other. said print head, comprising means for delaying said printhead. 11. 11. The print head according to claim 10, wherein the offset distance is moved over the medium in a scanning direction. Determining the delay by dividing by the linear velocity of the moving print head , said print head. 12. 8. The printhead of claim 7, wherein the radiation source comprises four radiation sources; All three are of substantially the same size and shape, and the fourth is of similar shape. but having a smaller size than the equally sized source. 13. 13. The printhead of claim 12, wherein two of the equal sized sources are scanned. arranged along a line that crosses the direction and separated from each other, the third one depending on the scanning direction. along the scanning direction, and both by a predetermined amount across the scanning direction. and the smaller source is overlapped with the equal-sized source in the scanning direction. The sources are shifted in the opposite direction, and are completely aligned with them in the scanning direction. said print head overlapping said print head. 14. 14. The printhead of claim 13, wherein all of the radiation sources are phased array lasers. Said print head consisting of a diode.